Ultrasonic devices are well known in the medical and dental field for use in tissue removal, or removal of organic and other types of deposits. When employed in the practice of periodontics, ultrasonic scalers are fitted with a pointed tip or end adapted for scraping calculus or tartar deposits. The ultrasonic vibrations of the tip facilitate the removal of such deposits on hard tissue, such as bone or teeth. In this type of application, the ultrasonic scaler includes a handpiece with a "pile" housed therein for generating the ultrasonic vibrations. A replaceable ultrasonic insert, fitted with the tip, is inserted into the end of the handpiece and connected to the pile for transferring the ultrasonic vibrations to the tip. A flow of water is also directed through the handpiece to cool the ultrasonic pile as it converts high frequency electrical energy to the mechanical vibrations. The water absorbs the heat generated by the pile, thereby maintaining the pile at an appropriate operating temperature. The water exits the insert via an orifice, is directed to the tip and, because of the ultrasonic vibrations of the tip, generates an aerosol cloud or mist. The water stream particles that are directed toward the tip, are broken into microdroplets which can create a large globe-shaped envelope, ranging in size up to 48 inches in diameter.
The aerosol cloud of microdroplets can also include small tissue fragments and droplets of body fluids, including blood, which become airborne and, unless specific precautions are taken by the surgeon or doctor, can be inhaled. It can be appreciated that various contagious viruses and other organisms can be transferred from the patient, via the aerosol cloud, to the surgeon. In addition, the aerosol cloud is disadvantageous for both the patient and the surgeon, in that after several minutes of utilization of the ultrasonic device, both the patient and the doctor can become wet or soaked.
Insofar as the water flow through the ultrasonic device is necessary for cooling, it cannot be interrupted during the operation of the device without overheating and potentially damaging the device. It is also believed that there may be a beneficial result of the ultrasonic water jet in the area of operation, as it is believed that the water jet provides cavitation for facilitating removal of stains and deposits.
Attempts have been made to control water jets in dental equipment, such as illustrated in U.S. Pat. No. 4,253,831 by Eaton, II. According to this patent, an aspirating dental device is fitted with a pliable sleeve over a contra-angle type of dental drill to form an airflow passage between the pliable sleeve and the handpiece itself. An airflow passage inlet exists near the working end of the dental handpiece, while a vacuum or suction is applied to the outlet end. It is believed that such a concept is inoperable as the sleeve must be somewhat pliable to be inserted on or removed from the irregular shaped dental device, and that being the case, the suction applied to the outlet end thereof would collapse the sleeve and interrupt or severely restrict the suction therethrough. The end result would be the inability to aspirate fluids at the working end of the device. Further, the pliable removable sleeve would be constricted around the dental device when the doctor grasps the device for use on a patient, thereby compromising the utility of the device. It should additionally be noted that the turbine exhaust of the Eaton, II air-driven dental drill is located within the airflow passage inlet. The high pressure exhaust from the dental drill will greatly reduce or nullify the low volume suction, and can result in no suction at all.
From the foregoing, it can be seen that a need exists for an improved mist or aerosol recovery device, usable with an ultrasonic scaler to reduce the spread of germs, viruses, and contaminated particles suspended in the cloud. A further need exists for a device that reduces the extent of the aerosol envelope, without reducing the cooling capability of the water stream. A related need exists for an attachment that reduces the amount of hot water that is dispensed from the ultrasonic device into the patient's mouth.
Yet another need exists for an aerosol recovery attachment that is removable from the conventional handpiece, is low cost, and thus is disposable for the surgeon.